T 0756/03 26-08-2005

Reasons for the Decision

1. The appeal is admissible.

2. Appellant's main and first auxiliary requests

2.1 In the decision under appeal, the opposition division came to the conclusion that the ground for opposition mentioned in Article 100(c) EPC prejudiced the maintenance of the patent as granted. According to the last feature of claim 1, the logic means included means for causing discharge of the defibrillator capacitor to the heart if any of the stored intervals between successive R-waves was less than a preset tachycardia rate cycle length limit (PCLL) during the second delay. The feature that the said intervals were "stored" represented subject-matter extending beyond the content of the application as filed.

2.2 The application as filed discloses an apparatus for defibrillating/cardioverting the heart. According to Figure 1 and column 4, lines 31-35 (all citations refer to the A1 publication), the apparatus comprises inter alia a memory 23 "for storing cardiac condition information such as R-R wave intervals and programmable data". The operation of the apparatus and, in particular, the function of the memory can be understood having regard to Figures 2 to 4 and the corresponding description. A so-called "abort algorithm", on the basis of which the apparatus operates, essentially consists of three steps.

According to a first step 34, after an arrhythmia is detected, a defibrillation capacitor is charged to a selected level to defibrillate the heart, if necessary. The abort algorithm operates with R-wave sensing during the charging of the capacitor and is accomplished by logic means (see column 2, lines 22-26). The detected R-R intervals are stored in the said memory (see column 5, lines 48-54 in combination with column 4, lines 31-35; claim 15, feature (c); claim 21, feature (d)).

Once the capacitor is fully charged, a first period is initiated. During this period (see claim 9, lines 27- 31), alternatively at its end (see column 2, lines 44- 49) or thereafter (see claim 1, feature (e)), a comparison is made, at step 42, between the "last" or "most recent" R-R interval detected while charging the capacitor and the value of PCLL (see Figure 2, step 42).

If the "last" or "most recent" R-R interval is greater than the value of PCLL, a second "non-committing" period is initiated, during which further monitoring of the heart activity is made (see column 6, lines 1-5) and a check is made, at step 46, whether "any" R-R interval detected during this period is less than PCLL (see Figure 2, step 46; column 2, line 58 to column 3, line 9; column 6, lines 12-16; claim 1, features (f), (g) and (h); claim 9, lines 35-38; claim 15, features (e), (f) and (g)). If this is the case, the capacitor charge is delivered to the heart immediately but synchronously with the second R-wave of the first fast interval detected during the non-committing period (see column 6, line 56 to column 7, line 3).

It results from the foregoing that the comparisons made at steps 42 and 46 substantially consist in comparing R-R intervals with the value of PCLL. However, they are different with regard to the number of times and the moment of the comparison. Whereas the step 42 requires a single comparison relying on the last R-R interval detected earlier within the charging time of the defibrillation capacitor, the step 46 repeats the comparison for each R-R interval detected during the second non-committing period until a fast interval is found being shorter than the value of PCLL. As to the R-R intervals detected while charging the defibrillation capacitor, they are stored in memory 23 in order to render the "last" R-R interval detected available for electronic treatment at a later time, i.e. for the comparison step 42.

2.3 The appellant took the view that the claimed expression "stored intervals" was an explicit formulation of a feature unambiguously deriving from the content of the application as filed read by a skilled person. As a support for this statement, the appellant argued that the apparatus was controlled by a microprocessor having a memory in which the R-R intervals were stored. This view is not convincing. It is not denied that the application as filed discloses a microprocessor having a memory (see column 4, lines 31-35; Figure 1). However, the function of this memory cannot be inferred from the description of the apparatus as such but only from the phases of the abort algorithm. In particular, whereas the original disclosure explicitly puts the execution of step 42 in direct relation to the microprocessor memory (see column 5, lines 48-54, in particular line 53), it does not permit to conclude beyond doubt that the memory also plays a role with regard to the execution of the further step 46. In the absence of any instruction in this respect, the skilled person would not understand that the teaching pertaining to the previous step 42 also applies to step 46. As a matter of fact, the feature of storing the R-R intervals detected during the second non-committing period is not absolutely necessary for carrying out the comparison step 46 (see point 2.5 below). In this respect, it does not matter that, as the appellant underlined, such a feature would make sense from a technical point of view. It is the requirement under Article 123(2) EPC that counts, according to which a feature representing an amendment has to derive in a direct and unambiguous way from the disclosure of the application as filed, as the respondent submitted. In the present case, this condition is not met.

2.4 The Board is also not convinced by the appellant's further argument that the skilled person, who had the instruction of sensing the R-waves and storing the R-R interval during the defibrillation capacitor charging phase in order to carry out the comparison step during the first period, would not interrupt the storing of R- R intervals during the second period because the original disclosure did not give any hint in this respect. As a matter of fact, the application as filed is completely silent as to whether the storing step should be carried out or not during the second period too. It is not admissible to interpret this lack of information as an implicit instruction to extend the storing step to the second period. The original disclosure rather leaves to the skilled person the initiative as to how the comparison during the second period should be carried out. The skilled person may well consider whether to store the R-R intervals or not. This, however, does not mean that the feature of storing can be derived in a direct and unambiguous way from the disclosure of the application as filed.

2.5 According to the appellant, the comparison step during the second period implied the necessity of stored rather than volatile values. This was convincingly contested by the respondent which drew attention to the fact that the R-R intervals might well be determined by a counter without the need to store any value. As already stated, the original disclosure does not give any information concerning the way the R-waves should be processed in order to determine the R-R intervals to be compared with the value of PCLL. Thus, any conclusion as to the necessity of storing the R-R interval must be considered as being speculative. It is essential that, unlike the comparison during the first period, each R-R interval detected during the second period is immediately checked until an interval is found being shorter than the value PCLL. This would not render a storing step during the second period necessary or even desired. As the respondent convincingly submitted, the feature that the capacitor charge was delivered to the heart immediately but synchronously with the second R-wave of the first fast interval detected during the non-committing period rather indicated that a storing step would not be meaningful.

2.6 In conclusion, the appellant's main and first auxiliary requests are not allowable because the ground for opposition pursuant to Article 100(c) EPC prejudices the maintenance of the patent as granted.

3. Appellant's second auxiliary request

3.1 Claim 1 of the second auxiliary request corresponds to claim 1 of the main request, in which the term "stored" is deleted and the last feature "in a manner that ..." is added (see point VI above).

3.2 In the appellant's view, the amendments avoided the problem of the conflicting requirements of Article 123 EPC, paragraphs 2 and 3, addressed to in decision G 1/93 (OJ 1994, 541). In line with this decision (see Headnote, point 1, last sentence), in the application as filed there was a basis in column 6, line 12-23 for replacing the term "stored" with the last feature added without violating Article 123(3) EPC. Regarding both amendments together, claim 1 as amended should be interpreted as involving a comparison of the R-R intervals detected during the second period, which did not necessarily require a storing step as resulted from the immediate discharge of the defibrillation capacitor effected on the second R-wave of the first fast interval detected.

3.3 The added feature is disclosed in column 6, lines 12-16 of the application as filed. As such it limits the protection conferred because the amended claim includes a further feature. However, the limiting effect cannot compensate for the extension caused by the deletion of the term "stored". Unlike claim 1 of the patent as granted which necessarily requires that the R-R intervals be stored during the second period, the amended claim 1 covers an embodiment in which the storing step is facultative. This interpretation is consistent with both the amendments made; with the first amendment by way of deletion because there is obviously no longer the obligation to store the said intervals, with the second amendment by way of addition because the term "immediately" may also be understood as implying that the discharge of the defibrillation capacitor is effected without any delay after the first fast R-R interval has been detected and stored, if desired only. Thus, the appellant's interpretation limits the scope of the claim in an undue way. It results that the added feature cannot constitute a basis for deleting the term "stored" without violating Article 123(3) EPC. In conclusion, the protection conferred is extended, as the respondent submitted.

3.4 Hence, the appellant's second auxiliary request is not allowable because of a violation of Article 123(3) EPC.